This invention relates particularly, but not by way of limitation, to a transformer housing providing a sealed passage for electrical leads from the transformer. More generally, it relates to an interface for communicating a plurality of electrical leads across a barrier, such as through a wall of the transformer housing.
A transformer housing with which a particular aspect of the present invention is concerned has a chamber defined in it. This chamber receives a transformer and an insulating fluid (e.g., oil). The transformer includes one or more primary and secondary windings which must be connected to power inputs and outputs located outside the chamber. To make these connections, electrical leads are connected to the respective transformer windings and to the respective inputs or outputs. These leads are connected across a wall of the housing which at least in part defines the chamber. This has typically been done using individual units each comprising an electrical member (e.g., a metal rod) and a bushing. These units are mounted in the wall of the transformer housing and electrical connections are made to the conductive portion of a unit on each side of the wall. The electrical member passing through the wall preferably is electrically insulated from the wall by the bushing since the wall of the transformer housing is typically made of electrically conductive material, and the bushing preferably seals with the wall to prevent leakage of the fluid from the chamber. An example of one such unit is the "SPEED MOUNT II" secondary bushing from Central Moloney.
Because these individual units have bare terminals to which the connections are made, adequate clearance space must be provided between adjacent units. Use of these units is labor intensive as the individual electrical connections are manually made. These combination electrical member/bushing units are also expensive. There is thus the need for an improved interface which provides a sealed, electrically insulated passage across a barrier, such as a transformer housing wall, in a more compact and less expensive manner than the aforementioned individual electrical member/bushing units. There is also the need for such an interface to provide for the electrical communication across the barrier without having to make all the individual connections required with existing bushing units.